Pass Context to http requests

[arminm]

I'm having a hard time using APM with OpenTracing with this client, because there's no way for me to pass a context (e.g. HTTP requests' req.Context()) to the functions that make an HTTP call (i.e. the Logical module which does Read, ReadWithData, List, etc with HTTP calls to the backend).

I would like to ask for allowing for context to be passed to the Logical client's functions so people can do fine grained tracing, as well as cancel a Vault request if the original request has been cancelled or times out.

[iusergii]

Is anything changed since Opentracing support ?